The present invention relates to an exchange system realized, for example, as a private branch exchange system.
This application is based on Japanese Patent Application No. 9-19395, filed Jan. 31, 1997 and Japanese Patent Application No. 9-35773, filed Feb. 20, 1997, the contents of which are incorporated herein for reference.
As known, in a large scale communication network, the kinds of exchange services required for an exchange system have increased more and more widely. An example of those exchange services will be an abbreviation dial service. To achieve this service, phone numbers of persons to be called, corresponding to predetermined abbreviation numbers, are stored as administrate data in a memory of an exchange system.
In an exchange system, a plurality of control systems (or exchange devices) are multiplexed to improve the reliability, and each of the plurality of control systems must store control data such as administrate data, maintenance data, and the like. Consequently, the entire exchange system must have a large memory capacity. Further, if the control systems are multiplexed, data transfer from an act system to a stand-by system is carried out in order that control data must correspond to each of the multiplexed control systems. However, in accordance with an increase of control data as described above, the time period required for the data transfer increases. If an obstacle appears in a system during the time period, normal exchange services cannot be provided securely and the reliability of the system is deteriorated.
In a conventional exchange system as described above, a plurality of control systems multiplexed to construct an exchange system, in order to improve the reliability, and same control data is stored in each of the plurality of multiplexes systems, so that the memory capacity of the exchange system is pressed heavily. In addition, a long processing time is required for performing data transfer and conversion processing to unify the control data to be stored in each of the multiplexed control systems, so that provision of normal exchange services cannot be secured, resulting in a drawback that the reliability of the system is deteriorated.
Control data set on a memory in an exchange system is backed up into an external storage device such as a hard disc or the like. In a method of back-up, control data on a memory is transferred to an external storage device at a predetermined time point or at a time point when a system manager issues a request. However, in this method, if another setting processing is carried out while control data is transferred to an external device such as a hard disc or the like, a problem occurs in that control data set by the other setting processing is not stored in the external storage device before a next timing.
In another method of back-up, a command for setting, updating, or changing the control data on the memory is stored in an external storage device every time when a maintenance man or a system manager inputs the command. In this method, however, there are drawbacks that control data changed by a telephone terminal cannot be reflected on an exchange system since the command is not input to the exchange system, and that the area on an external storage device for storing the history of inputted commands is limited so that the history of all commands cannot be stored.
Further, both of the methods described above result in a problem that data common to all the multiplexed control systems or to some of the control systems cannot be changed once by one single operation if an exchange system is constructed by a plurality of multiplexed control systems.
However, in registration of control data relating to extension numbers, types of telephone terminals, and the like, the scale of the exchange system is enlarged and the amount of control data to be set increases. For example, a large amount of control data must be registered, changed, or deleted, when operation of a new exchange system is started, when software of exchange service is updated, when control data is reconstructed due to a malfunction or the like, or when telephone terminals belonging to an exchange system are additionally provided, reduced, or moved. Therefore, an exchange system which is provided with a management device for managing operation such as retrieve operation, automatic generation of control data, or the like has been put to practical use, in order to avoid a situation as described above.
In this exchange system, however, a maintenance man or service manager must input commands for setting control data by a terminal for every item of a large amount of control data to be registered, changed, or deleted, so that much labor and time are required. A problem hence occurs in that the reliability of the exchange system is thus deteriorated.